1. Field of the Invention
This invention relates to a degas chamber useful in semiconductor and/or integrated circuit fabrication and, more particularly, to an improved mechanism for protecting and controlling failures in the degas operation.
2. Description of the Related Art
Numerous items can be manufactured from fluid consistently delivered to a reactor or processing tool. Manufacture takes place by loading the item into the processing tool and delivering a vaporized fluid above the item to accumulate a reactive species upon the item. Multiple deliveries of fluid will eventually produce a finalized item or product.
In order to form a consistent product, it is oftentimes beneficial that only fluid be delivered to the processing tool. If the fluid contains solid particles or gas bubbles, problems may arise. Unfortunately, the fluid delivery system in many instances might employ a gas motive force. For example, gas delivered under pressure to a chamber may force fluid within that chamber through a conduit into the processing tool. As gas drives liquid through the conduit, gas bubbles may become entrained within the liquid, and the combination of gas and liquid are deleteriously placed into the processing tool.
In an effort to deliver only liquid to the processing tool, a degas module is often placed between the liquid-driving mechanism (i.e., a mechanism which uses a gas motive force) and the processing tool. The degas module functions to remove gas bubbles or unwanted gaseous molecules from the liquid conduit prior to it entering the processing tool.
A degas module generally comprises a gas permeable conduit extending throughout a degas chamber. The gas-entrained liquid passes into the permeable conduit and, as the liquid passes across the conduit, gas is expelled through the conduit and into the chamber. A vacuum source is coupled in communication with the chamber to suction gas from the conduit into the chamber.
Oftentimes the permeable conduit will suffer a tear or leak, or the bushings around the conduit entering the chamber or exiting the chamber will leak. When this occurs, the volatile liquid within the conduit may transform to a solid state (e.g., crystallize) when exposed to a reacting gas. The reacting gas is generally a gas dissimilar from the motive gas, and can arrive through leaks within the chamber to the outside ambient, or from backstreaming into the chamber from the vacuum port.
A leak within the gas permeable membrane may allow more than gas bubbles or molecules to pass. The leak, if significant, may allow liquid to spill into the degas chamber or particles, which arise as a result of liquid inside the chamber, to form within the chamber and pass into the conduit. Particles placed into the liquid (or gas bubbles remaining in the liquid), and passage of the particles and/or gas into the downstream processing tool deleteriously affect the resulting product.
It is desirable to produce a degas module which can allow an operator to quickly and easily detect any and all leaks within the degas chamber and/or the gas permeable conduit. More importantly, the desirous degas module must be one which does not require disassembly of the module to determine those leaks. Disassembling the module may not uncover a leak within the module but, unfortunately, may cause a leak either during disassembly or during re-assembly. The gas permeable conduit, and bushings surrounding the conduit as they are fed into a degas module are somewhat delicate and fragile. Any movement of those items during disassembly may jeopardize their integrity and may therefore cause leaks which previously did not exist. Accordingly, an improved degas module must be derived which can be easily checked or "debugged" in a less invasive manner.